+++ /dev/null
-/*
- * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
- *
- * This program and the accompanying materials are made available under the
- * terms of the Eclipse Public License v1.0 which accompanies this distribution,
- * and is available at http://www.eclipse.org/legal/epl-v10.html
- */
-package org.opendaylight.netconf.nettyutil.handler;
-
-import io.netty.buffer.ByteBuf;
-import io.netty.buffer.ByteBufInputStream;
-import io.netty.buffer.ByteBufUtil;
-import io.netty.buffer.Unpooled;
-import io.netty.channel.ChannelHandlerContext;
-import io.netty.handler.codec.ByteToMessageDecoder;
-import java.io.IOException;
-import java.util.List;
-import org.opendaylight.controller.config.util.xml.XmlUtil;
-import org.opendaylight.netconf.api.FailedNetconfMessage;
-import org.opendaylight.netconf.api.NetconfMessage;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-import org.xml.sax.SAXException;
-import org.xml.sax.SAXParseException;
-
-public final class NetconfXMLToMessageDecoder extends ByteToMessageDecoder {
- private static final Logger LOG = LoggerFactory.getLogger(NetconfXMLToMessageDecoder.class);
-
- @Override
- public void decode(final ChannelHandlerContext ctx, final ByteBuf in,
- final List<Object> out) throws IOException, SAXException {
- if (in.isReadable()) {
- if (LOG.isTraceEnabled()) {
- LOG.trace("Received to decode: {}", ByteBufUtil.hexDump(in));
- }
-
- /* According to the XML 1.0 specifications, when there is an XML declaration
- * at the beginning of an XML document, it is invalid to have
- * white spaces before that declaration (reminder: a XML declaration looks like:
- * <?xml version="1.0" encoding="UTF-8"?>). In contrast, when there is no XML declaration,
- * it is valid to have white spaces at the beginning of the document.
- *
- * When they send a NETCONF message, several NETCONF servers start with a new line (either
- * LF or CRLF), presumably to improve readability in interactive sessions with a human being.
- * Some NETCONF servers send an XML declaration, some others do not.
- *
- * If a server starts a NETCONF message with white spaces and follows with an XML
- * declaration, XmlUtil.readXmlToDocument() will fail because this is invalid XML.
- * But in the spirit of the "NETCONF over SSH" RFC 4742 and to improve interoperability, we want
- * to accept those messages.
- *
- * To do this, the following code strips the leading bytes before the start of the XML messages.
- */
-
- // Skip all leading whitespaces by moving the reader index to the first non whitespace character
- while (in.isReadable()) {
- if (!isWhitespace(in.readByte())) {
- // return reader index to the first non whitespace character
- in.readerIndex(in.readerIndex() - 1);
- break;
- }
- }
-
- // Warn about leading whitespaces
- if (in.readerIndex() != 0 && LOG.isWarnEnabled()) {
- final byte[] strippedBytes = new byte[in.readerIndex()];
- in.getBytes(0, strippedBytes, 0, in.readerIndex());
- LOG.warn("XML message with unwanted leading bytes detected. Discarded the {} leading byte(s): '{}'",
- in.readerIndex(), ByteBufUtil.hexDump(Unpooled.wrappedBuffer(strippedBytes)));
- }
- }
- if (in.isReadable()) {
- NetconfMessage msg;
-
- try {
- msg = new NetconfMessage(XmlUtil.readXmlToDocument(new ByteBufInputStream(in)));
- } catch (SAXParseException exception) {
- LOG.error("Failed to parse received message", exception);
- msg = new FailedNetconfMessage(exception);
- }
-
- out.add(msg);
- } else {
- LOG.debug("No more content in incoming buffer.");
- }
- }
-
- /**
- * Check whether a byte is whitespace/control character. Considered whitespace characters: <br/>
- * SPACE, \t, \n, \v, \r, \f
- *
- * @param byteToCheck byte to check
- * @return true if the byte is a whitespace/control character
- */
- private static boolean isWhitespace(final byte byteToCheck) {
- return byteToCheck <= 0x0d && byteToCheck >= 0x09 || byteToCheck == 0x20;
- }
-}